Contraception GP Flashcards
Essentials for contraceptive prescribing
List the main contraceptive methods.
IUD = copper coil
IUS = progesterone coil
SDI = progesterone implant
POI = progesterone-only injectable
POP = progesterone-only pill
CHC = combined hormonal contraceptive
Which guidance advises on contraindications for contraceptive methods?
UK Medical Eligibility Criteria (UKMEC), based on evidence and consensus opinion
Adapted from international WHOMEC by FSRH (Faculty for Sexual and Reproductive Healthcare)
How many UKMEC categories are there, what do they mean?
UKMEC categories 1 to 4
- Always usable
- Broadly usable
- Counsel/caution
- Do not use
Examples for UKMEC 4 (contraindicated)?
All hormonal methods (CHC, POP, DMPA, IUS) contraindicated in current breast cancer
Combined hormonal contraceptives (CHC) in
- migraine with aura / focal migraine
- BP >160/95
- <6w post-partum (due to thrombosis risk <3w and reduced milk volume <6w)
- SLE with unknown or documented antiphospholipid antibodies
- major surgery with prolonged immobilisation
Definition of Pearl index?
Pearl index = number of pregnancies occuring per 100 women years (a women year defined as 13 menstrual cycles)
Limitations of Pearl index?
Limitations of Pearl index
- reflects perfect use - user-dependent methods (e.g. pills) have a higher Pearl index (pregnancy risk) in typical use / real life
- does not reflect natural change in pregnancy risk over time (index is given as 85 independent of age)
Examples of Pearl index for common contraceptive methods.
No method: 85 (of 100 women pregnant/year)
Condom: 2 (18 in typical use)
POP or CHC: 0.3 (9 in typical use)
DMPA: 0.2 (6 in typical use)
IUD (0.8) or IUS (0.2) in typical use
Subdermal implant most effective: 0.05 in typical use
Sterilisation: female 0.5 / male 0.15
What are Combined Hormonal Pills (CHC) made of?
An oestrogen and progesterone,
Oestrogen is ethinyloestradiol, mostly 30 micrograms (20, 30, 35, 50 available)
Progesterone generations:
- Norethisterone
- Levonorgestrel
- Desogestrel, Gestodene
- Drospirenone
First line choice of CHC (recommended by FSRH)?
A 30mcg pill containing either
- Norethisterone (Loestrin 30) or
- Levonorgestrel (Rigevidon, Ovranette, Microgynon, Levest, …)
Second line options of CHC, if woman experiences side-effects?
Oestrogenic side-ffects: nausea, headache, dizziness, breast tenderness, cyclical weight gain
- Try lower dose oestrogen e.g Loestrin 20, or
- more progesterone dominant e.g. Levonorgestrel-based pills
Progestogenic side-effects: weight gain, mood swings, acne, seborrhoea, hirsutism
- Try an oestrogen-dominant pill, or
- 3rd or 4th generation e.g. Gedarel, Marvelon, Femodene, Lucette
Breakthrough bleeding: Check compliance, check cervical screen up to date, do pelvic exam +/- STI screen
- Then, try higher dose oestrogen, or
- 3rd or 4th generation pill
How can a woman take the CHC pill, i.e. what regimes are there?
- Traditional 21/7 regime
- Shorter hormone-free interval e.g. 24/4
- Extended: 2 or 3 strips consecutively, followed by a 4 (up to 7) day break
- Unscheduled cycles: take continuously, with a 4 (up to 7) day break when breakthrough bleeding occurs
- Continuous: take pill every day whether breakthrough bleeding occurs or not
Advantages of extended CHC regimes and shortened hormone-free interval?
Extended regimes
- fewer menstrual symptoms like headaches, pain, bloating
- suppresses endometriosis and PMS
- reduced failure rate
Shortened hormone-free interval (4 days)
- less chance of ovulation
- resulting in lower failure rate
Endorsed by FSRH but unlicensed
Missed pill rules?
(for CHC except Qlaira and Zoely)
It is a missed pill once taken >24h late.
One missed pill: take missed pill together with today’s pill, continue with the rest of the pack, no further action
Two or more missed pills: take one missed pill together with today’s pill (discard remaining missed pills), continue with the rest of the pack, use extra precautions for 7 days, if unprotected sex in previous 7 days may need emergency contraception
How does taking CHC influence the risk of cancer?
A small increase in risk of breast and cervical cancer, which reduces after stopping and is back to normal after 10 years.
UKMEC is 1 for family history of breast cancer, 3 for BRCA mutation carriers, and 4 for current breast cancer.
Reduced risk of ovarian, endometrial and colorectal cancer.
No increase in risk of mortality or overall cancer risk.
How do CHC affect venous thrombosis (VTE) risk?
Annual risk of VTE (per 10,000 women)
- Not pregnant and not using CHC: 2
- 1st or 2nd gen CHC: 5-7
- 3rd or 4th gen CHC: 9-12
- pregnant: 29
- postpartum: 300-400
UKMEC regarding CHC and venous thrombosis?
UKMEC 4 (absolute contraindications)
- personal history of VTE
- known thrombogenic mutation
- age >35 and smoking >15/d
- major surgery and prolonged immobilisation
- SLE with antiphospholipid antibodies
UKMEC 3 (risks usually outweigh benefits)
- BMI >35
- first degree relative with VTE < age 45
- age >35 and smoking <15/d
- immobility unrelated to surgery (e.g. wheelchair)
Co-cyprindiol (Dianette) should only be prescribed as a treatment for severe acne (where topical treatments and oral antibiotics have failed) or hirsutism (MHRA).
How do CHC influence arterial risk?
- 1-2 fold increased risk of MI and stroke
- 1 to 2 extra cases per 10,000 women/year
- not influenced by type of progesterone
Consider CV risk factors / UKMEC criteria
POP do not increase arterial risk
UKMEC advice on CHC and arterial risk?
UKMEC 4 (absolute contraindications)
- age >35 and smoking >15/d
- migraine with aura
- BP >160/95
- h/o IHD, TIA or stroke
- complicated valvular or congenital heart disease
- SLE with antiphospholipid antibodies
UKMEC 3 (risk usually outweighs benefits)
- age >35 and smoking <15/d
- migraine with aura >5y ago
- BMI >35
- controlled hypertension
- BP >140/90
- diabetic with nephropathy, retinopathy, neuropathy or vascular disease
What is the Evra patch and how is it used?
A CHC that delivers 20mcg ethinyloestradiol and 150mcg norelgestromin a day
Apply first day of menstruation and replace weekly for 3 weeks, week 4 patch-free
Reduced efficacy if weighing >90kg
If used preceding 7d then can remain detached 48hrs efore efficacy reduced, similarly patch-free interval can be extended to 9d.
FSRH endorses extended regimes as for CHC pills.
Advice to give women using CHC when prescribing antibiotics?
Based on FSRH advice of 2011, no additional precautions are necessary.
The exception are enzyme-inducing drugs such as rifampicin/rifabutin.
Remind women that extra precautions are however required if they develop diarrhoea or vomiting.
Advice regarding herbal remedies and hormonal contraception?
Avoid St John’s Wort with any hormonal contraceptive.
Ask about herbal remedies use in woman with unscheduled bleeding.
Which drugs are enzyme-inducers?
Carbamazepine, eslicarabazepine, oxacarbazeine
Phenobarbitol, phenytoin, primidone
Rifampicin, rifabutin
Moderate: Topiramate, St John’s wort
Numerous HIV drugs
Not inducers: Benzos, Gabapentin/pregabalin, Lamotrigine, Levetiracetam, Valproate
How long does the effect of enzyme-inducers last?
It begins within 2 days and can last up to 4 weeks, so extra precautions must be continued 4 weeks after cessation.
Which contraceptive methods are affected by enzyme-inducers, which are not?
Affected by enzyme inducers: CHC, POP, SDImplant, Ullipristal and Levonelle
Not affected are: POI (DMPA injection), IUS, IUD
